1. Field of the Invention
The present invention relates to a fuel supply device that supplies a fuel injection system or a carburetor with pressured fuel and, particularly, to a fuel pump having a brush-less motor.
2. Description of the Related Art
A fuel pump having a brush-less motor is disclosed in U.S. Pat. No. 4,955,790 or JP-A-1-105395. This brush-less motor is controlled by a drive circuit having a comparatively small power switch circuit, in which motor-starting current is limited. However, it is not possible to form such power switch circuit in a one-chip IC unit, because a large capacity is necessary for such a power switch circuit. Usually, about 3-7 ampere is necessary to drive such a fuel pump, while a switch circuit formed on a one-chip IC unit that can switch about 1-2 ampere is only available these days.